The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 2012
Filed:
Oct. 01, 2010
David Hum, Livermore, CA (US);
David Hum, Livermore, CA (US);
Bridgelux, Inc., Livermore, CA (US);
Abstract
A compound light source that compensates for changes in electrical conversion efficiency with increasing operating temperature is disclosed. The compound light source generates light of a design intensity at a design temperature in response to a drive current flowing through the light source. The light source includes a primary light source and a compensating light source. The primary and compensating light sources convert an electrical current passing therethrough to light, each light source being characterized by an electrical conversion efficiency that decreases with increasing temperature and that also decreases with increasing current. The compound light source includes a temperature sensor that measures the temperature of the primary light source and a current splitting circuit that divides the drive current between the primary and compensating light sources to compensate for the decrease in efficiency of the primary light source with temperature above the design temperature.